Quartz lamp envelope with molybdenum foil having oxidation-resistant surface formed by ion implantation

Abstract

A quartz lamp envelope includes a press seal, at least one molybdenum foil feedthrough extending through the press seal to the lamp interior, and an external electrical lead connected to the molybdenum foil. The molybdenum foil has an oxidation-inhibiting material, such as chromium, aluminum and combinations thereof, embedded in a surface layer thereof by ion implantation. The electrical lead has an oxidation-inhibiting coating, such as silicon carbide, silicon nitride and combinations thereof, formed by plasma-enhanced chemical vapor deposition. Alternatively, the electrical lead can have an oxidation-inhibiting material embedded in a surface layer thereof by ion implantation.

What is claimed is: 
     
       1. A lamp assembly comprising: a quartz lamp envelope that encloses a sealed lamp interior, said lamp envelope including a press seal;   at least one treated molybdenum foil electrical feedthrough extending through said press seal to said lamp interior, said treated molybdenum foil having an oxidation-inhibiting material embedded in a surface layer thereof by means of an ion implantation process, the thickness of said treated molybdenum foil being no greater than the thickness of said molybdenum foil before being so treated.   
     
     
       2. A lamp assembly as defined in claim 1 wherein said oxidation-inhibiting material is selected from the group consisting of chromium, aluminum, silicon, titanium, tantalum, palladium and combinations thereof. 
     
     
       3. A lamp assembly as defined in claim 1 wherein said oxidation-inhibiting material comprises chromium. 
     
     
       4. A lamp assembly as defined in claim 1 wherein said oxidation inhibiting material comprises aluminum. 
     
     
       5. A lamp assembly as defined in claim 1 wherein said surface layer has a thickness in the range of about 20 to 100 angstroms. 
     
     
       6. A lamp assembly as defined in claim 1 further including an incandescent filament located in said lamp interior and coupled to said molybdenum foil. 
     
     
       7. A lamp assembly as defined in claim 1 further including a discharge electrode located in said lamp interior and coupled to said molybdenum foil. 
     
     
       8. A lamp assembly as defined in claim 1 further including a molybdenum electrical lead connected to said molybdenum foil, said electrical lead having an oxidation-inhibiting material embedded in a surface layer thereof. 
     
     
       9. A lamp assembly as defined in claim 8 wherein said oxidation-inhibiting material is embedded in the surface layer of said electrical lead by ion implantation. 
     
     
       10. A lamp assembly as defined in claim 2 further including a molybdenum electrical lead connected to said molybdenum foil, said electrical lead having an oxidation-inhibiting coating thereon. 
     
     
       11. A lamp assembly as defined in claim 10 wherein said oxidation-inhibiting coating is selected from the group consisting of silicon carbide, silicon nitride and combinations thereof. 
     
     
       12. A lamp assembly as defined in claim 10 wherein said oxidation-inhibiting coating comprises silicon carbide. 
     
     
       13. A lamp assembly as defined in claim 11 wherein said oxidation-inhibiting coating is applied to said electrical lead by plasma-enhanced chemical vapor deposition. 
     
     
       14. A lamp assembly as defined in claim 10 wherein said oxidation inhibiting coating has a thickness in the range of about 50 to 1000 angstroms. 
     
     
       15. A lamp assembly comprising: a quartz lamp envelope that encloses a sealed lamp interior, said lamp envelope including a press seal; and   at least one treated conductive foil electrical feedthrough extending through said press seal to said lamp interior, said treated conductive foil having an oxidation-inhibiting material embedded in a surface layer thereof by means of an ion implantation process, the thickness of said treated molybdenum foil being no greater than the thickness of said molybdenum foil before being so treated.   
     
     
       16. A lamp assembly as defined in claim 15 wherein said oxidation-inhibiting material is selected from the group consisting of chromium, aluminum, silicon, titanium, tantalum, palladium and combinations thereof. 
     
     
       17. A lamp assembly as defined in claim 15 further including an external electrical lead connected to said conductive foil, said electrical lead having an oxidation-inhibiting coating thereon. 
     
     
       18. A lamp assembly as defined in claim 17 wherein said oxidation-inhibiting coating is applied to said electrical lead by plasma-enhanced chemical vapor deposition. 
     
     
       19. A lamp assembly as defined in claim 18 wherein said oxidation-inhibiting coating is selected from the group consisting of silicon carbide, silicon nitride and combinations thereof. 
     
     
       20. A lamp assembly as defined in claim 15 wherein said conductive foil comprises molybdenum. 
     
     
       21. A method of making a lamp assembly comprising the steps of: ion implanting an oxidation-inhibiting material into a surface layer of a molybdenum foil strip; and   sealing the molybdenum foil strip into a press seal of a quartz lamp envelope to form an electrical feedthrough to a sealed lamp interior.   
     
     
       22. A method of making a lamp assembly as defined in claim 21 wherein the step of ion implanting includes the step of ion implanting a material selected from the group consisting of chromium, aluminum and mixtures thereof into the surface layer of said molybdenum foil strip. 
     
     
       23. A method of making a lamp assembly as defined in claim 21 further including the steps of forming an oxidation inhibiting coating on an external electrical lead by plasma-enhanced chemical vapor deposition, and   attaching the coated electrical lead to said molybdenum foil strip.   
     
     
       24. A method of making a lamp assembly as defined in claim 21 further including the steps of ion implanting an oxidation-inhibiting material into a surface layer of an external electrical lead, and   attaching the electrical lead to said molybdenum foil strip.